Preparation and performance of thermosensitive poly(N‐isopropylacrylamide) hydrogels by frontal photopolymerization

Abstract

In this study, frontal photopolymerization was applied to the fabrication of thermosensitive poly(N‐isopropylacrylamide) (PNIPAm) hydrogels. The influence of experimental conditions and reactant components on the feature of the polymerization front was investigated. The morphology of the samples indicated the successful preparation of PNIPAm hydrogels. The mechanical properties and thermal stability of the obtained hydrogels are discussed. The results indicated that the performance of the hydrogels is related to their microstructure and the type of crosslinkers. The swelling behavior and drug delivery ability were determined under different temperature conditions. The hydrogels exhibit a classical thermoresponsive behavior, which was also demonstrated by the DSC results. Therefore, frontal photopolymerization can be an alternative method for the preparation of PNIPAm hydrogels under mild conditions. © 2019 Society of Chemical Industry

Front velocity dependence on vinyl ether and initiator concentration in radical‐induced cationic frontal polymerization of epoxies

“…[12][13][14][15] It was rediscovered by Pojman and studied in the 1990s [16][17][18] and has seen recent rapid growth through applications such as composites, 19,20 cure-on demand materials and adhesives, 21,22 deep-eutectic solvents 23 and hydrogels. [24][25][26][27][28] In a thermal frontal polymerization process, an input of thermal energy at a specific area initiates a propagating localized reaction zone that travels through the entire material, where monomer is converted into polymer as propagation occurs. 29 Typically, most monomers capable of supporting fronts proceed by free-radical mechanisms due to their high rate of reactivity and exothermicity.…”

Photoinitiating systems and kinetics of frontal photopolymerization processes – the prospects for efficient preparation of composites and thick 3D structures

“…2 Washington and Steinbock proposed a mechanism to prepare poly(N-isopropylacrylamide). 40 Investigation of the mechanism of frontal polymerisation of hydrogels from a poly(acrylic acid), 41,42 polyacrylamide, 43 and others 4,5,26,[44][45][46][47][48][49] was also presented.…”

Thermoresponsive hydrogels based on renewable resources

“…Researchers also investigate polymerization techniques for synthesis of hydrogels. For instance, Su et al . developed thermoresponsive hydrogels by using frontal photopolymerization, whereas Fundueanu synthesized microspheres by suspension polymerization.…”